Warning: The article below features HIGHLY GRAPHIC content that is likely to offend or upset.

Further harrowing images of the final moments of former Libyan ruler Muammar Gaddafi have been made public.

GlobalPost has obtained video, allegedly shot on the cellphone of one of the rebel fighters who captured Gaddafi, that shows him being attacked by one of his captors. Various reports have questioned whether the former Libyan leader was sodomized with what appears to be a stick or metal rod in the opening moments of the video. The video shows an attacker striking Gaddafi with the object. The camera pulls away quickly afterward.

Libya's interim leader, Mustafa Abdul-Jalil, has promised an investigation into the exact circumstances of how Gaddafi met his demise. Initial reports suggest Gaddafi was killed in the crossfire as his supporters clashed with revolutionary forces seizing control of his hometown of Sirte.

But Abdul-Jalil raised a new possibility on Monday, suggesting that Gaddafi could have been killed by his own supporters to prevent him from implicating them in past misdeeds under his regime.

"Let us question who has the interest in the fact that Gaddafi will not be tried. Libyans want to try him for what he did to them, with executions, imprisonment and corruption," he said. "Free Libyans wanted to keep Gaddafi in prison and humiliate him as long as possible. Those who wanted him killed were those who were loyal to him or had played a role under him, his death was in their benefit."

It is widely believed that the videos circulating online show the Libyan leader after he was captured by rebel forces alive, but in a bloodied and confused state. A series of images released by international news agencies appear to show Gaddafi's corpse with a bullet wound to the head (See the images here: WARNING - GRAPHIC CONTENT)